Riser Lifecycle Management System, Computer Readable Medium and Program Code

ABSTRACT

Systems, computer readable medium, program code, and methods for monitoring and managing a plurality of marine riser assets are provided. An example of a system includes a computer and a computer readable medium containing a program code of instructions that when executed by the computer, cause the computer to perform operations for tracking the subsea deployment and retrieval of each of a plurality of riser joints. The operations can include receiving riser joint identification data from a riser joint identification indicator connected to the respective riser joint during the operational deployment thereof, and identifying the respective riser joint being operationally deployed to thereby track the deployment thereof. The operations can also include receiving riser joint identification data from the riser identification indicator of the respective riser joint during retrieval thereof, and identifying the respective one or more riser joints being retrieved to thereby track the retrieval thereof.

RELATED APPLICATIONS

This application is a continuation of and claims the benefit of andpriority to U.S. patent application Ser. No. 13/300,155, titled “RiserLifecycle Management System, Program Product, and Related Methods,”filed on Nov. 18, 2011, which is a continuation of and claims thebenefit of and priority to U.S. patent application Ser. No. 12/029,376,titled “Riser Lifecycle Management System, Program Product, and RelatedMethods,” filed on Feb. 11, 2008, now U.S. Pat. No. 8,074,720, and isrelated to U.S. patent application Ser. No. 10/951,563, now U.S. Pat.No. 7,328,741, titled “System for Sensing Riser Motion,” filed on Sep.28, 2004, each incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to riser management systems. Moreparticularly, the present invention relates to systems, computerreadable media, program code, and related methods for monitoring andmanaging a plurality of marine riser assets.

2. Description of Related Art

A problem presented by offshore hydrocarbon drilling and producingoperations conducted from a floating platform or vessel is the need toestablish a sealed fluid pathway between each borehole or well at theocean floor and the work deck of the vessel at the ocean surface. Thissealed fluid pathway is typically provided by a drilling riser system.Drilling risers, which are utilized for offshore drilling, extend fromthe drilling rig to a blowout preventer (BOP). Similarly, productionrisers extend from and provide communication between a subsea wellheadsystem and the floating vessel.

A typical marine drilling riser permits passage of drill pipe which isused for pumping lubricating mud down the well during drillingoperations, return of drilling mud that has been pumped through thedrill pipe into the main tube of the riser, and any associated drillcuttings, and provides a connection of the drilling vessel to the wellabove the subsea BOP stack. The drilling riser can be disconnected fromthe well above the BOP stack, allowing the drilling vessel to retrievethe riser and temporarily move from the drill site should the need arise(i.e., during a hurricane event, or a malfunction). The BOP stack,having remained on the wellhead, provides for containment of a live wellwhile the vessel is not on location. Upon return, the vessel can deploythe riser, reconnect to the BOP stack, and reestablish hydrocarboncommunication with the well.

The marine drilling riser also permits control of the well should theBOP stack have to be functioned. This is typically associated withdrilling through a zone with geological fluid pressure that issubstantially higher than that which the drilling mud can contain.During such events, the BOP is functioned, and well control isre-established by pumping an appropriate density mud thought the killline and eventually circulating it back to the surface via the chokeline. The marine drilling riser also permits improvement of mudcirculation velocity. When needed, this is accomplished by pumpingadditional mud through the booster line and injecting it into the riserbore at the BOP stack. This increases the volume of mud in the riser;improving the return speed. The marine drilling riser further permitsdelivery of hydraulic fluid to the BOP stack control system. Such fluidis supplied through a dedicated external hydraulic line.

The drilling riser, for example, is typically installed directly from adrilling derrick on the platform of the vessel by connecting a series ofriser joints connected together. After connecting the riser to thesubsea wellhead on the seabed, the riser is tensioned by buoyancy cansor deck mounted tensioner systems. The riser is projected up through anopening, referred to as a moon pool in the vessel, to working equipmentand connections proximate an operational floor on the vessel. Indrilling operations, the drill string extends through a drilling riser,with the drilling riser serving to protect the drill string and toprovide a return pathway outside the drill string for drilling fluids.Similarly, in producing operations, a production riser is used toprovide a pathway for the transmission of oil and gas to the work deck.

Basic components of a riser system typically include, from the mud lineand extending to the surface: a hydraulic wellhead connector whichpermits connection to a subsea wellhead; a BOP stack used for wellcontrol; a lower marine riser package which permits disconnect andreconnect of the marine riser at the BOP stack; multiple marine riserjoints normally in the form of bare and buoyant joints each outfittedwith a choke and kill line, a booster line, and a hydraulic line; and atermination joint which is a special riser joint where external linesare terminated and diverted to the appropriate facility on the vessel.For example, the kill line is terminated and connected to the mud pumpvia a high pressure flexible line. The components also include a tensionring which provides for the interface of the marine riser to thehydro-pneumatic riser tensioner designed to provide lateral loadresistance while providing a somewhat constant vertical tension; and atelescopic joint typically made of two sliding pipes sealed together viaan elastomer primarily used is to decouple the motion of the vessel,while permitting the riser tensioner system to apply a near constanttension on the marine riser. The components also include a diverter usedfor diverting of the unwanted gas in the marine riser; a gimbal locatedon the rig floor used during running and retrieval of the marine riserto dampen the pitch motion of the vessel, and a marine drilling riserspider used during the mating of each riser section to the next.

Other more specialized riser equipment includes a fill-up valve designedto prevent collapse of the riser pipe due to the differential pressurebetween the inside of the riser pipe and the surrounding water, aninstrument riser joint typically used to monitor the tension and bendingdue to environmental conditions which allows for adjustment in toptension and vessel positioning, vortex suppression equipment which helpsuppress vortex induced vibrations typically found in conditions of highcurrent and long riser length, and an emergency riser release whichprovides a specialized riser release system to prevent catastrophicfailure typically found in conditions where incorrect vessel positioningor extreme environmental conditions may occur.

During a typical field installation, the marine riser components areindividually lifted from the deck, connected to each other at the riserspider, and run down. Riser joints, which comprise the major length ofthe riser string, are fabricated in lengths ranging from 50′ to 90′.During the running procedure, the portion of the riser string that isfully made up is landed on the riser spider. The next riser joint isthen picked up and placed just over the spider, immediately above thesuspended riser string. The two riser sections are then joined by meansof a mechanical connector, etc. The most common type for a riser jointprovides a bolted flange configuration.

Marine risers are subjected to impact loads as well as unexpected sideloads, which can damage fragile electronics. Marine risers are alsosubjected to environmental loads as well as vessel-induced loads. Theassociated environmental parameters include, among other things, waveheight and period, water depth, current, wind, and tides. In the subseaenvironment, hydrostatic pressure can reach 4,500 psi in currentdeepwater areas, and probably will reach 5,500 psi within a few years,and the seawater temperature can be as cold as 30° F. The hightemperature of the drilling mud could also impact electronic and sensorequipment, particularly electronic equipment attached directly to theriser pipe (joint) body. The vessel-induced loads include the appliedtop tension necessary to maintain the optimum shape for a riser string,and those imparted by the marine riser string due to motion of thevessel as it is subjected to wave, wind, and current loading. The mostcritical component of environmental loads is generally the current loaddirectly imparted on the riser string. The current loads typically varywith the water depth, but are generally much stronger near the surface.

Some locations around the world, such as the West of the Shetlands andthe Gulf of Mexico, offer unique challenges associated with strongcurrents. In the Gulf of Mexico, for example, an environmental eventestablishes a seasonal “Loop Current”, which moves in a circular patternreaching a diameter a hundred miles or more. Such loop currents impartexceptionally high environmental loads on a riser, often for weeks at atime. High current loading can result in shedding of vortices past amarine riser string, which, if coupled with unfavorable riser damping,can result in violent motion of a marine riser string, typically in across flow direction. This is commonly referred to as “Vortex InducedVibration” or “VIV.” The large amplitude of the riser motion during aVIV event can result in elevated stress levels in the riser string,which, in turn, dramatically reduces the fatigue life of the individualriser joints. A single fatigue event can potentially result in thecatastrophic failure of the marine riser string. Worse yet, a VIV eventcan take place in higher modes, for example, such as where only a smallportion of the riser string, possibly hundreds of feet below the watersurface, is excited and experiences VIV. Recognized by the inventor isthat in such a scenario, an observer on the vessel, looking down at thevisible portions of the riser string, would see no evidence of this VIVevent. Fortunately, catastrophic failure of risers has been few and farbetween.

A goal or series of goals for both drilling and production risers is tomanage stresses and loading of individual riser sections to provide forfatigue analysis, and thus, allow the operator to formulate an enhancedinspection, maintenance, and riser joint rotation program. If a singleriser joint in a riser string fails or otherwise exceeds an operationalconstraint resulting in a requirement for immediate maintenance, anentire riser string may have to be retrieved and rerun. In deepwateroperations, it might take two or more days to run or retrieve a marineriser. Given the approximate rate of well over $500,000 per day for a5^(th) generation drilling vessel, such a scenario would cost theoperator over a million dollars just to establish communication with thesubsea well. This point should illustrate the importance of saving timeduring the running and retrieving of the riser. It should alsoillustrate the importance of lost time, and the associated cost,resulting from a riser component failure. There have been, however,until now, no effective systems or methods of efficiently tracking riserassets, efficiently tracking cumulative stress or other loading on eachriser asset, or accurately determining or differentiating expectedstress levels between vessels or fields in order to properly forecastrequired maintenance.

SUMMARY OF THE INVENTION

Recognized by the inventor, therefore, is the need for a system,computer readable medium, computer program, and methods of managingriser assets, especially riser joints, which can provide asset managersa list of all the riser assets allocated to each specific vessel andprovide a further breakdown of those assets that are currently deployed,are on deck, or are out for maintenance, along with the expected returndate; a list of upcoming scheduled maintenance events; an estimate ofthe amount of operational life being expended by a particular riserasset; and an estimate of the total amount of cumulative operationallife used by a particular riser asset, along with the details of themost damaging events (i.e., a certain hurricane event). Also recognizedis the need for a system, computer readable medium, computer program,and methods of managing riser assets, especially riser joints, whichinclude a central database that can be used by field and maintenancepersonnel to maintain and communicate critical riser asset information,and that can enhance both routine maintenance scheduling and the processof identifying a requirement for an unscheduled maintenance event. Alsorecognized is the need for such a system, computer readable medium,computer program, and methods which can provide detailed information onriser maintenance history and critical/relevant manufacturinginformation, and provide a capability to properly track riser assets sothat they can be moved from one vessel to another with their historyintact.

Further recognized is the need for such a system, computer readablemedium, computer program, and methods which can provide a time stamp foreach riser deployment to permit the determination of where, in the watercolumn, each riser asset was located for any particular drilling orproduction campaign, which can, in turn, provide the user withinformation to reconstruct a riser string configuration of anyparticular deployment to thereby analyze riser asset performance andpreferred positioning. Also recognized is the need for a system,computer readable medium, computer program, and methods which can allowa user to optimally position a specific riser joint at a specificposition (depth) along the riser string, for example, based on an amountof operational life available (remaining), for example, in order tomatch a riser joints having a high amount of operational life remainingwith riser string depths expected to encounter a higher stress.

Still further, recognized is the need for a system, computer readablemedium, computer program, and methods of managing riser assets,especially riser joints, which include provisions for controlling ariser tensioning system to extend the operational life of the variousriser assets and to control riser performance such as, for example, whenencountering vortex induced vibration.

In view of the foregoing, various embodiments of the present inventionadvantageously provide a system, computer readable medium, computerprogram, and methods of managing riser assets, especially riser joints,which can provide asset managers a list of all the riser assetsallocated to each specific vessel and provide a further breakdown ofthose assets that are currently deployed, are on deck, or are out formaintenance, along with the expected return date; a list of upcomingscheduled maintenance events; an estimate of the amount of operationallike being expanded by a particular riser asset; and an estimate of thetotal amount of operational life used by a particular riser asset, alongwith the details of the most damaging events (i.e., a certain hurricaneevent). Various embodiments of the present invention also provide asystem, computer readable medium, computer program, and methods ofmanaging riser assets, especially riser joints, which include a centraldatabase that can be used by field and maintenance personnel to maintainand communicate critical riser information, and that can enhance bothroutine maintenance scheduling and identifying a need for an unscheduledmaintenance event.

Various embodiments of the present invention also provide a system,computer readable medium, computer program, and methods which canprovide detailed information on riser asset maintenance history andcritical/relevant manufacturing information; and which can provide thecapability to properly track riser assets so that they can be moved fromone vessel to another with their history intact. Various embodiments ofthe present invention also provide a system, computer readable medium,computer program, and methods which can provide a time stamp for eachriser asset deployment to permit the determination of where, in thewater column, each riser asset was located for any particular drillingcampaign, which can, in turn, provide the user with information toreconstruct a riser string configuration of any particular deployment tothereby analyze riser asset performance and preferred positioning.Various embodiments of the present invention also provide a system,computer readable medium, computer program, and methods that can allow auser to optimally position a specific riser joint at a specific position(depth) along the riser string, for example, based on an amount ofoperational life available (remaining), for example, in order to match ariser joints having a high amount of operational life remaining withriser string depths expected to encounter a higher stress. Variousembodiments of the present invention also provide a system, computerreadable medium, computer program, and methods of managing riser assets,especially riser joints, which include provisions for controlling ariser tensioning system to extend the operational life of the variousriser assets and to control riser performance such as, for example, whenencountering vortex induced vibration.

More specifically, various embodiments of the present invention includea computer program, stored on a tangible computer memory medium,operable on a computer to monitor and manage a plurality of marine riserassets positionable at one or more separate vessel locations. Theprogram can include instructions that when executed by a computer causethe computer to perform various operations including receiving riserjoint identification data for each of a plurality of riser joints from ariser joint identification sensor during deployment from a vessel toform a marine riser string, with each riser joint carrying anidentification indicator connected thereto, and identifying therespective riser joint being deployed to thereby track the deploymentthereof responsive to the riser joint identification data received bythe riser joint identification sensor, which is itself received from arespective identification indicator. The operations can also includereceiving riser joint identification data for one or more of theplurality of riser joints from the riser joint identification sensorduring retrieval thereof, and identifying the respective one or moreriser joints being retrieved to thereby track the retrieval thereofresponsive to the riser joint identification data received by the riserjoint identification sensor from the respective identificationindicator.

According to an exemplary configuration, each identification indicatorconnected to a separate one of the plurality of riser joints carriesindicia readable by the riser joint identification sensor to provideinformation about the respective riser joint sufficient to provide forseparately identifying each of the plurality of riser joints beingdeployed and retrieved from each other of the plurality of riser jointsduring subsea deployment.

Correspondingly, the operations can also include tracking the subseadeployment and retrieval of each of the plurality of riser joints,recording a timestamp indicating when each respective riser joint of theplurality of riser joints was deployed and/or retrieved, determining arelative deployed position location of the each of the plurality ofriser joints deployed from the vessel, and/or virtually constructing themarine riser string configuration responsive to the riser jointidentification data for each of the plurality of riser joints receivedduring deployment thereof.

The operations can also or alternatively include predicting a magnitudeof a load imposed on a subsea wellhead system associated with the riserstring responsive to corresponding riser load data for at least a subsetof a plurality of riser joints forming the marine riser string. Theoperations can also or alternatively include receiving load data foreach of the plurality of riser joints retrieved from a correspondingplurality of riser joint measurement instrument modules connectedthereto, monitoring loading of each of the plurality of riser jointswhen deployed responsive to the load data provided by the plurality ofriser joint measurement instrument modules, estimating a deployed riserjoint loading condition for each of the plurality of riser jointsresponsive to the load data of one or more of the plurality of riserjoints, and providing an alarm responsive to the estimated deployedriser joint loading condition nearing an operating design or serviceenvelope of one or more of the plurality of deployed riser joints.

The operations can also or alternatively include monitoring loading ofeach of the plurality of deployed riser joints responsive to the loaddata provided by the plurality of riser joint measurement instrumentmodules, monitoring tensioning system tension settings, applied risertension, and tensioner stroke, and providing data to control adjustingthe tensioning system tension settings to automatically continuallyapply optimum riser tension responsive to the load data. The operationscan also or alternatively include detecting an anomaly in the load dataof one or more of the plurality of riser joints when existing, andproviding an alarm responsive to the detection of the anomaly.

The operations can also or alternatively include estimating fatiguedamage to each of the plurality of riser joints responsive to the loaddata of the one or more of the plurality of riser joints, and providingan alarm responsive to the estimated fatigue damage of one or more ofthe plurality of deployed riser joints exceeding a preselectedoperational limit.

The operations can also or alternatively include comparing deployedriser joint sensor readings of a riser joint measurement instrumentmodule associated with one or more of the plurality of riser jointsforming the riser string to sensor readings for at least two riserjoints of the plurality of riser joints forming the riser string tothereby determine an integrity of the riser joint measurement instrumentmodule and to flag sensor readings emanating from the respectiveinstrument module when the integrity is determined to be questionable,removing flagged data associated with a faulty instrument module fromactive record data, and optionally replacing the removed data withcorresponding predicted data generated by a riser sensor data predictor.

The operations can also or alternatively include identifying amalfunctioning riser joint measurement instrument module associated withone or more of the plurality of riser joints forming the marine riserstring when operationally deployed, and signaling one or more adjacentriser joint measurement instrument modules to bypass the malfunctioningriser joint measurement instrument module to thereby providesubstantially continuous load data acquisition for each riser jointmeasurement instrument module positioned below the malfunctioning riserjoint measurement instrument module.

The computer program can include instructions represented, for example,by one or more of the following computer elements: a riser assetdeployment and location tracker adapted to receive subsurface deploymentand relative location positioning data for a plurality of riser jointsto be deployed to form a marine riser string, a riser asset load sensordata receiver adapted to receive load data for each of the plurality ofriser joints when deployed to form the marine riser string, and a riserasset fatigue determiner adapted to estimate a condition of each of theplurality of riser joints responsive to the received riser joint loaddata and/or riser stress data determined from the received riser jointload data for each separate one of the plurality of riser joints, alongwith others disclosed herein.

Various embodiments of the present invention also provide a riserlifecycle management system for monitoring and managing a plurality ofmarine riser assets positionable at one or more separate floatingvessels each generally having a floor, a well bay extendingtherethrough, a local shipboard communication network carried by thevessel, and a shipboard computer in communication with the localshipboard communication network and including a processor, and memorycoupled to the processor to store operating instructions therein. Thesystem, according to an embodiment of the present invention, includesthe vessel, a riser joint identification sensor positioned at oradjacent the well bay and operably coupled to the shipboardcommunication network, and a plurality of riser joints each carrying anidentification indicator and a riser joint measurement instrumentmodule, deployable from the vessel to form a riser string. According toan embodiment, the system identifies the respective riser joint beingdeployed to thereby track the deployment thereof responsive to the riserjoint identification data received by the riser joint identificationsensor, which is itself received from a respective identificationindicator on each of the plurality of riser joints. According to anembodiment, the system also or alternatively includes a riser jointidentification sensor positioned at or adjacent the well bay andoperably coupled to the communication network to facilitate trackingriser joint deployment and retrieval.

According to an embodiment, the riser joint measurement instrumentmodules are each positioned to sense a load imposed on a separate one ofthe plurality of deployed riser joints. According to an embodiment, thesystem also or alternatively includes a riser joint load data receiverconnected to the vessel at or adjacent the surface of the sea (e.g.,positioned in the well bay, or connected to a riser joint adjacent thesurface) and operably coupled to the local shipboard communicationnetwork to receive direct or multiplexed load data for each of theplurality of deployed riser joints from the plurality of riser jointmeasurement instrument modules. The riser joint load data receiver andeach of the plurality of riser joint measurement instrument modules canestablish a communication pathway through a water column associated withthe riser string.

The system also includes a riser asset management program stored in thememory of the shipboard computer to monitor and manage a plurality ofriser assets. The vessel riser asset management program can includeinstructions that when executed by the shipboard computer, cause theshipboard computer to perform various operations including receivingriser joint identification data from the riser joint identificationsensor for each of the plurality of riser joints during deployment fromthe vessel to form the riser string, identifying the respective riserjoint being deployed to thereby track the deployment of the riser joint,and determining a relative deployed position location of the each of theplurality of deployed riser joints within the riser string. The vesselriser asset management program can further include instructions thatwhen executed by the shipboard computer, cause the shipboard computer toperform the operations of receiving riser joint identification data fromthe riser joint identification sensor for one or more of the pluralityof riser joints during retrieval and identifying the respective joint tothereby track the retrieval of the joint.

The vessel riser asset management program can further includeinstructions that when executed by the shipboard computer, cause theshipboard computer to perform the operations of receiving the load datafor each of the plurality of deployed riser joints from the riser jointdata receiver, monitoring loading of each of the plurality of deployedriser joints responsive to the load data provided by the plurality ofriser joint measurement instrument modules, estimating a riser jointloading condition for each of the plurality of deployed riser jointsresponsive to the load data of the one or more of the plurality ofdeployed riser joints, and providing an alarm responsive to theestimated loading condition nearing an operating design or serviceenvelope.

The system can also include at least one computer to remotely manageriser joints for a plurality of separate vessel locations defining ariser lifecycle management server having a processor and memory coupledto the processor to store operating instructions therein, a globalcommunication network providing a communication pathway between theshipboard computer and the riser lifecycle management server to permittransfer of riser asset information between the shipboard computer andthe riser life cycle management server, and a riser lifecycle managementprogram stored in the memory of the riser lifecycle management server tomanage a plurality of riser assets positioned at a plurality of separatevessel locations. The riser lifecycle management program can includeinstructions that when executed by the riser lifecycle managementserver, cause the riser lifecycle management server to perform theoperations of receiving riser joint deployment and location data for theplurality of deployed riser joints, receiving riser joint load historydata for the plurality of deployed riser joints from the shipboardcomputer, transforming load history data received in the time domainfrom the shipboard computer into load history data in the frequencydomain, and sending riser load history data in the frequency domain tothe shipboard computer.

The operations can also include determining fatigue of each of theplurality of deployed riser joints responsive to the received riserjoint load history data, estimating remaining fatigue life responsive tothe received riser joint load history data and riser joint materialproperties, scheduling routine maintenance events for each of theplurality of deployed riser joints, and scheduling unscheduledmaintenance events responsive to a load history anomaly in the riserjoint load history data resulting in engagement of a preset fatigue lifetrigger level requiring inspection. The operations can further includereconstructing a riser string configuration (i.e., performing a virtualconstruction) of any one of the plurality of riser joints deployed atany one of the plurality of separate vessel locations responsive to theriser joint deployment and location data associated with the respectiveriser string, and predicting a magnitude of a load imposed on a subseawellhead system associated with the respective riser string responsiveto corresponding riser load history data for at least a subset of aplurality of riser joints forming the respective riser string.

The system can still further include a data warehouse assessable to theprocessor of the riser lifecycle management server and including atleast one database storing asset information, such as, for example,riser joint identification data, riser joint deployment and locationdata, and riser joint load history data for the plurality of riserjoints deployed at the plurality of separate vessel locations, and atleast one database accessible to the processor of a shipboard computerand storing asset information, such as, for example, riser jointidentification data, riser joint deployment and location data, and riserjoint load history data for each of the plurality of riser jointsdeployed from a respective vessel.

Various embodiments of the present invention also provide methods ofmonitoring and managing a plurality of marine assets. An exemplarymethod can include the steps of operationally deploying a plurality ofriser joints from a vessel to form an operationally deployed marineriser string, reading riser joint identification data from a riser jointidentification indicator connected to the respective riser joint, foreach of the plurality of riser joints during the operational deploymentthereof using a riser joint identification sensor (e.g., RFID, barcode,or contact memory reader), and identifying the respective riser jointbeing operationally deployed to thereby track the deployment thereofresponsive to the riser joint identification data read from therespective riser joint identification indicator. The method alsoincludes retrieving one or more riser joints of the plurality ofoperationally deployed riser joints, reading riser joint identificationdata from the riser identification indicator of the respective one ormore riser joints during retrieval thereof; and identifying therespective one or more riser joints being retrieved to thereby track theretrieval thereof responsive to the riser joint identification data readfrom the respective riser joint identification indicator. According toan exemplary configuration, each riser joint identification indicatorconnected to a separate one of the plurality of riser joints contains orcarries information about the respective riser joint sufficient toseparately identify each of the plurality of riser joints being deployedand retrieved from each other of the plurality of riser joints duringsubsea deployment. Utilizing the indicia, the method also includestracking the subsea deployment and retrieval of each of the plurality ofriser joints. The method can also include recording a timestampindicating when each respective riser joint of the plurality of riserjoints is deployed, and recording a timestamp indicating when eachrespective riser joint of the plurality of riser joints is retrieved.

According to an embodiment of the present invention, the method can alsoinclude receiving riser joint identification data from a riser jointidentification sensor positioned within a well bay of the vessel duringdeployment of the plurality of riser joints, and virtually constructing(reconstructing) the marine riser string configuration responsive to theriser joint identification data for each of the plurality of riserjoints received during deployment thereof. The method can also includedetermining a relative deployed position location of the each of theplurality of riser joints deployed from the vessel. The relativedeployed location comprises a relative deployed position location of therespective riser joint along a length of the deployed marine riserstring relative to each other of the plurality of deployed riser joints,the water line, or other physician reference.

The method can also include the step of receiving load data for each ofthe plurality of riser joints from a plurality of riser jointmeasurement instrument modules. The load data is provided through relayof the data from each of the plurality of riser joints to a riser jointpositioned adjacent the respective riser joint until reaching a riserload data receiver. The method can also or alternatively include thestep of receiving load data for each of the plurality of riser jointsfrom a corresponding plurality of riser joint measurement instrumentmodules, monitoring loading of each of the plurality of deployed riserjoints responsive to the load data provided by the plurality of riserjoint measurement instrument modules, estimating a riser joint loadingcondition for each of the plurality of deployed riser joints responsiveto the load data of one or more of the plurality of deployed riserjoints, and providing an alarm responsive to the estimated loadingcondition nearing an operating design or service envelope of one or moreof the plurality of deployed riser joints. The steps can also includeestimating fatigue damage to each of the plurality of deployed riserjoints responsive to the load data of the one or more of the pluralityof deployed riser joints, and providing an alarm responsive to theestimated fatigue damage of one or more of the plurality of deployedriser joints exceeding a preselected operational limit. The steps canfurther include detecting an anomaly in the load data of one or more ofthe plurality of deployed riser joints when existing, and providing analarm responsive to the detection of the anomaly.

The method can also or alternatively include the step of receiving loaddata for each of the plurality of riser joints from a plurality of riserjoint measurement instrument modules, whereby the load data is providedthrough relay of the data from each of the plurality of riser joints toa riser joint positioned adjacent the respective riser joint untilreaching a riser load data receiver. The steps can also includemonitoring loading of each of the plurality of deployed riser jointsresponsive to the load data provided by the plurality of riser jointmeasurement instrument modules, monitoring tensioning system tensionsettings, applied riser tension, and tensioner stroke, and providingdata to control adjusting the tensioning system tension settings toautomatically continually apply optimum riser tension responsive to theload data.

Various embodiments of the present invention also provide variousmethods relating to monitoring and managing a plurality of marine riserassets. According to an embodiment of the present invention, a method ofmonitoring and managing a plurality of marine riser assets can includethe steps of receiving riser joint identification data from a riserjoint identification sensor positioned within a well bay, anddetermining a relative deployed position location of each of a pluralityof riser joints deployed from the vessel to form a marine riser string.Each of the riser joints correspondingly include indicia readable by ariser joint identification sensor to separately identify each one of theplurality of riser joints from each other of the plurality of riserjoints. The method can also include receiving load data for each of theplurality of riser joints from a plurality of riser joint measurementinstrument modules which can each be connected to a corresponding one ofthe plurality of deployed riser joints, and monitoring loading of eachof the plurality of deployed riser joints responsive to the load dataprovided by the plurality of riser joint measurement instrument modules.

According to another embodiment, a method of monitoring and managing aplurality of marine riser assets includes the steps of determining arelative deployed position location of the each of a plurality of riserjoints deployed from a vessel and having indicia readable by a riserjoint identification sensor to separately identify each one of theplurality of riser joints from each other of the plurality of riserjoints during deployment thereof, receiving load data for each of theplurality of deployed riser joints from a plurality of riser jointmeasurement instrument modules connected to at least a subset of theplurality of deployed riser joints, monitoring loading of each of theplurality of deployed riser joints responsive to the load data providedby the plurality of riser joint measurement instrument modules,estimating a riser joint loading condition for each of the plurality ofdeployed riser joints responsive to the load data of one or more of theplurality of deployed riser joints, and providing an alarm responsive tothe estimated loading condition nearing an operating design or serviceenvelope for one or more of the plurality of deployed riser joints.

According to another embodiment, a method of monitoring and managing aplurality of marine riser assets positioned at one or more separatevessel locations can include the steps of receiving riser jointdeployment and location data for each one of a plurality of deployedriser joints deployed at one of a plurality of separate vessel locationscarrying the respective riser joint, receiving riser joint load historydata for each of the plurality of riser joints deployed at the pluralityof separate vessel locations from an associated shipboard computer,transforming riser joint load history data received in the time domaininto load history data in the frequency domain, and determining a levelof damage of each of the plurality of deployed riser joints responsiveto at least one of the following: the received riser joint load historydata or the transformed riser joint load history data.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the features and advantages of theinvention, as well as others which will become apparent, may beunderstood in more detail, a more particular description of theinvention briefly summarized above may be had by reference to theembodiments thereof which are illustrated in the appended drawings,which form a part of this specification. It is to be noted, however,that the drawings illustrate only various embodiments of the inventionand are therefore not to be considered limiting of the invention's scopeas it may include other effective embodiments as well.

FIG. 1 is an environmental view of a system for monitoring and managinga plurality of marine riser assets according to an embodiment of thepresent invention;

FIG. 2A-B is an environmental view of a portion of the system formonitoring and managing a plurality of marine riser assets according toan embodiment of the present invention;

FIG. 3 is a perspective view of a riser joint carrying communication andidentification hardware according to an embodiment of the presentinvention;

FIG. 4 is a schematic block diagram of a riser joint measurementinstrument module according to an embodiment of the present invention;

FIG. 5 is a combination perspective view and schematic block diagram ofa tensioning system according to an embodiment of the present invention;

FIG. 6 is a schematic block diagram of a riser lifecycle managementprogram stored in the memory of a riser lifecycle management serveraccording to an embodiment of the present invention; and

FIG. 7 is a schematic block diagram of a riser asset management programstored in the memory of a shipboard computer according to an embodimentof the present invention.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, which illustrate embodiments ofthe invention. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theillustrated embodiments set forth herein. Rather, these embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the invention to those skilled in the art.

FIGS. 1-7 illustrate an embodiment of a Riser Lifecycle MonitoringSystem (RLMS) which provides an integrated tool designed to improve thelifecycle performance of a marine riser through the application ofremote diagnostics, online asset management, and readily accessibleriser asset maintenance history, and to permit remote management ofriser assets, with particular emphasis on riser joints. The riserlifecycle management system includes integrated hardware andsoftware/program code (product) components which can be combined in acentral database preferably located on shore. This database can storeasset information on every riser lifecycle management system equippedriser in the world. It also can permit transfer of a riser asset fromone vessel to another while retaining all historic data. The vesselcomputers, in turn, can retrieve the data from sensors placed, forexample, on each riser asset. Such riser deployment records can becommunicated between the riser asset sensors and the computer on boardthe ship by means of a simple radio frequency identification or “RFID”tag or other identification indicia on the riser asset and anappropriate receiver on a portion of the vessel such as, for example,the drilling riser spider. As the riser joint or other asset is beingrun or retrieved, the receiver, for example, on the riser spider, sensesthe unique riser asset ID tag stored on the RFID chip, and communicatesthat information to the shipboard computer along with a time stamp. Theriser lifecycle management system beneficially provides for acquisitionof riser load history data. Such acquisition can include gatheringsensor data, multiplexing that data, and communicating it through thewater column up to a vessel, while allowing for an acceptable level offault tolerance. The data acquired depends on the type of sensor used onthe riser asset. For example, if only accelerometers are used on theriser joint, then a real time map of the riser accelerations would beavailable. Additional processing by either the shipboard or shore-basedcomputer, for example, can be performed to convert the information to areal time map of the riser stresses. Alternatively, if strain or riserjoint curvature is measured on, for example, a riser joint, then riserjoint stress data can be calculated by a relatively simple manipulationof the data. The riser stresses, as a function of time, can then befurther manipulated to estimate the condition of the riser joint from anasset operational life standpoint. Such data provided by variousembodiments of the system can also allow for scheduled and unscheduledmaintenance and for control of an associated riser tensioning system.

More specifically, FIGS. 1-2B illustrate a plurality of offshoredrilling and/or production systems 21, and a riser lifecycle managementsystem 30 to remotely manage marine riser assets positioned at one ormore separate vessel/drilling/production system locations, according toan embodiment of the present invention. The drilling and/or productionsystem 21 can include a deployed riser pipe or conductor defining ariser string 23 extending between subsea wellhead system 25, such as,for example, the illustrated subsea wellhead, and a floating vessel 27,such as, for example, a dynamically positionable vessel. The riserstring 23 includes multiple riser sections or joints 29 connectedtogether, for example, by a bolted flange or other means known to thoseskilled in the art. The vessel 27 includes a well bay 31 extendingthrough a floor of the vessel 27, and typically includes a spider 32positioned on an operational platform 33 in a well bay 31 to support theriser string 23 when riser joint connections are being made or brokenduring running or retrieval of the riser string 23. Note, though variousembodiments of the present invention apply to both drilling andproduction risers, the drilling riser was selected for illustration anddiscussion due to the need for additional components such as, forexample, the Lower Marine Riser Package and Blowout Preventer shownwithin the subsea wellhead system 25, which is not generally required ina production riser.

The vessel 27 also includes a tensioning system 35, 35′, located on theoperational platform 33 which provides both lateral load resistance andvertical tension, preferably applied to a slip or tensioning ring 37attached to the top of the riser string 23. The tensioning system 35,35′ includes a riser tensioner controller 39 (FIG. 5) positioned tocontrol tensioning of the riser string 23 when fully deployed. Thevessel 27 also includes a shipboard computer 41 in communication with alocal shipboard communication network 43, e.g., LAN. The shipboardcomputer 41 can include a processor 45, and memory 47 coupled to theprocessor 45. Also in communication with the shipboard communicationnetwork 43 is a receiver/transmitter 44 providing, for example,satellite-based communication to onshore facilities. At least onedatabase 49 accessible to the processor 45 of the a shipboard computer41 is also provided which can be used to store asset information foreach of the plurality of riser joints deployed from the vessel 27 canalso be provided. As will be described in more detail below, such assetinformation can include riser joint identification data, riser jointdeployment and location data, and riser joint load history data for eachof the plurality of riser joints deployed from the vessel 27.

According to an embodiment of the present invention, the riser lifecyclemanagement system 30 includes portions onshore and portions at each ofthe vessel locations. The portion of the system 30 located at an onshoreor other centralized location or locations can include at least onecomputer to remotely manage riser assets for a plurality of separatevessel locations defining a riser lifecycle management server 51positioned in communication with an onshore local area communicationnetwork 53. The riser lifecycle management server 51 can include aprocessor 55 and memory 57 coupled to the processor 55. Also incommunication with the onshore communication network 53 is areceiver/transmitter 54 providing, for example, satellite-basedcommunication to a plurality of vessels/drilling/production facilitieseach having a receiver/transmitter 44. This portion of the system 30 canalso include a global communication network 61 providing a communicationpathway between the shipboard computers 41 of each respective vessel 27and the riser lifecycle management server 51 to permit transfer of riserasset information between the shipboard computers 41 and the riser lifecycle management server 51.

Note, the memory 45, 55, can include volatile and nonvolatile memoryknown to those skilled in the art including, for example, RAM, ROM, andmagnetic or optical disks, just to name a few. It should also beunderstood that the preferred onshore server and shipboard computerconfiguration is given by way of example in FIGS. 1 and 2A-B and thatother types of servers or computers configured according to variousother methodologies known to those skilled in the art can be used.Particularly, the server 51, shown schematically in, for example, FIG. 1represents a server or server cluster or server farm and is not limitedto any individual physical server. The server site may be deployed as aserver farm or server cluster managed by a serving hosting provider. Thenumber of servers and their architecture and configuration may beincreased based on usage, demand and capacity requirements for thesystem 30.

At the heart of this portion of the system 30 is a data warehouse 63which can store relevant data on every piece of riser lifecyclemanagement system equipped riser components anywhere in the world. Thedata warehouse 63 is assessable to the processor 55 of the riserlifecycle management server 51 and can be implemented in hardware,software, or a combination thereof. The data warehouse 63 can include atleast one centralized database 65 configured to store asset informationfor a plurality of riser joints 29 and other riser assets of interestdeployed at a plurality of separate vessel locations. The assetinformation can include, for example, the part number, serial number,relevant manufacturing records, operational procedures, and allmaintenance records (including detailed information on the nature of themaintenance), just to name a few. This information is generally keyedinto the system 30 at the time of manufacture or maintenance. Thedatabase 65 can also retain deployment and load history information,which is acquired automatically from shipboard computers 41 located oneach riser lifecycle management system equipped vessel 27. The shipboardcomputers 41, in turn, can retrieve the data from one or moreidentification devices 71 (see, e.g., FIG. 3) preferably placed on eachriser joint 29 or other riser or other asset to be tracked.

According to an embodiment of the present invention, the riseridentification and deployment data for each riser joint 29 (or otherriser asset of interest) is communicated, for example, to the shipboardcomputer 41 by means of a tag such as, for example, an RFID chip or tag71 (see, e.g., FIG. 3) positioned on each riser joint 29, and anappropriate riser joint identification sensor or receiver 73 positioned,for example, at or adjacent the well bay 31, preferably on the spider32, if used, and operably coupled to or otherwise in communication withthe shipboard computer 41 through the local shipboard communicationnetwork 43. As a riser joint 29, for example, is being run or retrieved,the sensor/receiver 73 on the spider 32 senses the unique riser asset IDstored on the RFID tag 71, and it communicates that information to theshipboard computer 41 along with a time stamp. The shipboard computer 41then compares ID data with the list of recently recorded tags. If aduplicate asset is reported, it is disregarded. That is, when utilizingautomated reading sensors, the same riser asset may be scanned multipletimes while being landed on the spider 32 or during the normal course ofhandling. As such, the preferred handling procedures can includedisregarding duplicate records or duplicate reads within a preselectedtime period. Note, although RFID tags 71 provide certain advantages,other acceptable identification means can include such devices ascontact memory buttons, barcodes, or other readable memory devices.

Communication of riser load history data for each deployed riser joint29 (or other riser asset of interest) is far more complex. As will bedescribed in more detail below, communication of load data for eachriser joint 29 can require sensing and multiplexing load data throughthe water column data, while permitting for an acceptable level of faulttolerance. Various computer program elements associated with the onshoredatabase 65 and/or the shipboard computer 41 then use the riser loadhistory to monitor the health of the marine riser assets, and make anyappropriate recommendations for the timing and the nature of the nextmaintenance event.

As indicated above, according to an embodiment of the present invention,the database 65 (and/or database 49) can include, e.g., three, basiccategories of data: data keyed-in by an operator, data acquiredautomatically from an on-board sensor or computer, and finally dataderived directly by a computer program element from manipulation ofstored information. Basic fields of the database 65 and/or 49, accordingto an embodiment of the present invention, are described below, withrespect to database 65.

With respect to keyed-in data, the database 65 can include for eachriser asset, a serial number, part number and revision letter,manufacturing records, maintenance records, and operational serviceprocedures. The serial number provides the unique serial number of theparticular riser asset. The part number and revision letter providedocumentation where a riser asset is revised during its normal life. Themanufacturing records can provide critical records typically requiredduring routine maintenance or condition monitoring. For example,material properties and weld types used in fabrication can be employedto determine fatigue life as the riser asset is subjected to operationalloads. Conversely, certain manufacturing non-conformances, and theirdisposition, along with any revision date details, can be of great valueduring routine maintenance procedures where repairs may be necessary.The maintenance records provide a number of records that are documentedduring routine or during one-time maintenance of the riser asset. Thestructure of the maintenance records optimally include references to thereason for maintenance, where, when, and who carried out the work, andany special instructions for future maintenance. The operational serviceprocedures provide documentation of manufacturer's recommendedoperational procedures. The operational procedures are preferably storedas a separate location and linked to the part number in a mannertransparent to the user, to enhance application of updates by themanufacturer.

With respect to automatically acquired data, the database 65 can includefor each riser asset, deployment records, and one or more load historytables, along with a tensioner log and/or other vessel data. Thedeployment records can provide data identifying where and when theparticular riser asset was used. As such, a deployment record wouldreference a particular field, the time stamp when the riser was run, andthe time stamp when it was retrieved. Additional deployment informationof value, such as the location of the riser asset relative to the waterline, can also be stored or automatically determined based on thedeployment sequence and the length of each riser joint 29. According toan embodiment of the present invention, the deployment records aretransmitted to the database 65 via an RFID tag, which is encapsulatedwithin the riser asset at a particular location. As will be discussed inadditional detail below, movement of the RFID tag 71 past an RFIDreader/sensor 73 located, for example, on the riser spider 32, wouldtrigger the RFID tag 71 to send a signal to the sensor/receiver 73.

The load history tables can provide a complete picture of the loadimposed on the riser asset. The load history tables can include those inthe time domain and in the frequency domain. The load history tablesprovided in the time domain can provide real time riser loading for someuser-defined length of time (e.g., 3 months). Load history data olderthan the defined length of time, or alternatively, a combination of sucholder data along with the newly data, however, can be, and preferably isretained in the frequency domain, which would span all available riserload history. It is noted that the riser load history in the time domainis used for calculating riser loads in the frequency domain. Inaddition, the time domain records can be used for extracting extrememagnitudes of riser loads and the particular event they were associatedwith, and can be used for internal validation of the results derivedfrom the frequency domain data.

The measured time-domain based data can depend on the type of sensorused on the riser asset. For example, if only accelerometers are used ona riser joint 29 to identify individual riser joint loading, then a realtime map of the riser accelerations would be provided. Additionalprocessing could then be employed to convert the information to a realtime map of the riser stresses. For example, a models database (notshown) can be used to model the loads imposed on each deployed riserjoint 29 based on the map of the riser accelerations, and/or determinedcurvature and/or direction of one or more of the deployed riser joints29. Alternatively, if strain is measured on the riser joint 29, eitherthrough direct or indirect means, riser joint stress data can becalculated by a relatively simple manipulation of the strain data incombination with the previous knowledge of one or more riser assetparameters, such as, for example, riser joint “Stress AmplificationFactor” (SAF) in relation to the riser load sensor (measurementinstrument) location. Regardless of the type of measurement instrumentsensor or module placed on the riser joint 29 or other riser asset, thestructure of the database 65 can provide sufficient flexibility forfuture replacement and upgrade of the measurement instrument sensor ormodule equipment to that of a different type.

Note, a distinction has been made between time domain based andfrequency domain based data. Dynamic data is generally represented inthe time domain. For example, a graph showing the height (amplitude) ofa wave as a function of time for two years is a simple time history ofthe wave represented in time domain. This information can also berepresented in the frequency domain, generally in a far more compact,but at the cost of loosing some detail. For example, in the instancedescribed above, instead of tracing the height of the wave as a functionof time, one can create a table with a hundred rows, each representing arange of wave heights (or more preferably the RMS of the wave heights),and also a period and a probability associated with each wave height andperiod combination. The more rows in the table, the finer the range ofthe wave height, and thus, the better the resolution. As can beexpected, two years worth of wave height data if represented in timedomain at a sampling rate of once a second could result in over 60million data points, while the same information if represented infrequency domain could result in a table with as few a hundred datapoints. The frequency domain table, however, generally looses theinformation associated with wave-to-wave transients. Further, numericaloperations on frequency domain data sets are usually significantly moreefficient, but at the cost of loosing clarity during transients (in thiscase, in between two waves) and often requires spot checks withanalytical results from the time domain data to ensure accuracy.Frequency domain analyses are, however, accurate and adequate in mostcases, and in particular for evaluation of fatigue, according to anembodiment of the present invention.

The tensioner log can provide storage of various parameters such as, forexample, tension setting, applied tension, and tensioner stroke, whichcan be used alone or in conjunction with the riser joint load historydata to determine various settings necessary to adjust riser jointloading and to formulate control signals to perform real-timeadjustments, described in more detail later.

With respect to computed data, the database 65 can include for eachriser asset, a riser asset Stress Amplification Factor (SAF) table, theload history table in the frequency domain, a maximum amplitude matrix,and estimated fatigue life remaining. The riser asset SAF table canprovide a compact table that lists the critical locations (positions) onthe riser asset where the fatigue computations should take place, suchas at the location of the connecting flanges. The SAF table can alsoprovide the SAF, itself, for each respective location, along with theSAF reference information (e.g., nominal pipe OD and wall thickness).

The frequency domain-based load history table, as noted previously, canprovide the operator with a comprehensive map of the loads imposed oneach specific riser joint 29, and ultimately, loads imposed on theentire riser string 23. The frequency domain-based load history tablecan be used to evaluate, for example, the total fatigue damage impartedon the riser asset. This information can be computed by thetransformation of a large volume of time domain-based riser load historyinto a relatively compact table in the frequency domain. A computerprogram element can perform the transformation and can update the tableon regular intervals (e.g., once a day, or on the fly in response to aquery, etc.). Regardless of the type of data gathered by the loadingmeasurement instrument sensors/modules (e.g., accelerations, strain,curvature, etc.) on the riser asset, the frequency domain table can bemanipulated to contain only certain quantities that are of particularinterest (e.g., strains or stresses). In other words, twotransformations may take place at the same time in order to prepare thefinal table in frequency domain, the data conversion (calculating ormodeling) to produce a quantity of interest, and a data conversion fromthe time domain to the frequency domain.

The maximum amplitude matrix can provide maximum amplitude values of oneor more parameters of interest. As the volume of data stored isrelatively small, the maximum amplitude figures can be retained for eachriser asset for each drilling/completion operation, referencing the nameof the field and also the well.

The riser lifecycle management system 30 also includes various shipboardand riser carried components. For example, shipboard computer 41, alongwith shipboard communication network 43, database 49, RFID tags 71, andriser joint identification sensor or receiver 73, have already beenidentified. Further, the system 30 can also include riser jointmeasurement instrument modules 91 each positioned to sense a loadrepresented by strain, riser pipe curve, or accelerometer data, etc.imposed on a separate one of the riser joints 29 forming the riserstring 23, a riser joint load data receiver 93 mounted or otherwiseconnected to the vessel 27 at or adjacent the surface of the sea andoperably coupled to the local shipboard communication network 43 toreceive load data for each of the deployed riser joints 29 from theriser joint measurement instrument modules 91, and a subsurfacecommunication medium 95 illustrated as provided via a series of ROVreplaceable wireless data telemetry stations providing a communicationpathway between each of the joint measurement instrument modules 91 andthe riser joint load data receiver 93 through a water column associatedwith the riser string 23. As shown in FIGS. 3 and 4, each instrumentmodule 91 (e.g., data telemetry station) can include a processor 101 incommunication with at least one sensor element 103, cache memory 105 tostore collected load data, a power source 107 preferably including abattery or other energy storage device, and a datatransmitter/multiplexer 109 for providing both collected and receivedloading data to the riser joint load data receiver 93, either directly,or via another one or more of the other instrument modules 91. A moredetailed discussion follows later which includes a discussion of otherconfigurations:

The measurement instrument modules 91 can determine the magnitude of theloads imposed on the riser string 23 to calculate the magnitude of thestress at various locations on the riser joint 29 or other riser asset.There are a number of methods under which the riser stresses can bemeasured. A preferred option is one that reads the riser pipe strain atthe sensor 103, since conversion of strain data to stresses is fairlystraightforward and can be done via a relatively simple computer programelement. Alternatively, the riser dynamics can be obtained viaaccelerometers, which may require a more complex set of operations forconversion to material stress from which the operational (e.g., fatigue)life can then be calculated. Other measurement options are, however,within the scope of the present invention. In either case, the load datasent to the riser lifecycle management server 51 can be in either rawdata or converted to local stresses by the shipboard computer 41, orsome intermediate form if some processing is accomplished by theinstrument modules 91.

According to an embodiment of the present invention, the sensor 103 iscarried by a thin clamp-on composite mat (not shown), which can be usedto accurately determine the deflection in the riser joint 29. In suchconfiguration, the mat is preferably about 3 feet long and coversapproximately 170 degrees of the circumference of the riser joint 29.Each mat contains optical fibers connected to an electronic sensor 103that is tuned to measure the wavelength of the light in the fibers. Asthe stiffness of the composite mat is substantially lower than thematerial forming the riser joint 29, the mat assumes the same curvatureas the riser joint 29 to which it is connected, thus changing the lengthof the fiber optic wires embedded in the mat and the measuredwavelength. As noted above, various other methodologies of positioningor carrying sensor 103 as known to those skilled in the art are withinthe scope of the present invention.

In a preferred configuration, the instrument readings taken by eachmeasurement instrument module 91 are transmitted from one riser joint 29or other asset to the next, multiplexed with the current riserinstrument readings, and forwarded until it reaches the vessel mountedreceiver 93. This receiver 93, in turn, sends the full data stream tothe shipboard computer 41 for processing and communication back to theriser lifecycle management server 51 and onshore database 65. While datamultiplexing is a well understood concept, communication though thewater column introduces specific challenges. Various options for datatelemetry are hardwire, acoustics, electromagnetics, and lasertelemetry.

Hardwire transmission media is probably the most straightforward methodfor communication of a large amount of data. The hardwire option,however, has some significant disadvantages. Among others, a damagedwire, especially near the top of the riser string 23, could result istotal loss of data from a significant majority of the riser joint 29 orother assets. Also, a hardwire option would typically require watertightstabs at each riser joint 29. When running and retrieving the riserstring 23, these stabs are subject to a somewhat hazardous environmentin terms “abuse” and contaminants, which are ever present in riseroperations. The hardwire option might be more practical as a jumperbetween two adjacent riser joints 29, but ideally only as a short-termsolution when the primary riser data telemetry has failed. Such anoption would, nevertheless, typically require some level of ROVintervention.

Acoustics is probably the most established form of communication forunderwater data telemetry. Acoustics offers a number of advantages andsome disadvantages, both of which are well-understood. At very shortranges (about 200 feet), a data rate of 500 kbps is achievable whileoperating at a carrier frequency of ˜1 MHz. This bandwidth is in excessof that required for telemetry over a range that spans two riser joints29 or other riser assets. According to an embodiment of the systemimplementing acoustics, each riser asset is equipped with a transceiverthat receives data, ignores the part not addressed to it, multiplexesthe incoming data with its own sensor readings, codes it with itsidentification, and then transmits the combined data packet to the nextriser asset, which uses the same routine to add more data and pass iton. According to a preferred configuration, each riser asset isinitially programmed to only communicate with the riser assets locatedimmediately above and below it having a measurement instrument module91; ignoring the data intended for any other riser asset. Thissequencing is carried out during riser deployment. In the event that adata telemetry system on a riser asset malfunctions, a signal from thesurface, for example, is sent which traverses all instrument moduleequipped riser assets and carries out a re-sequencing of thetransceivers so that the malfunctioning riser asset is removed from thechain. Alternatively, the instrument module 91 above the malfunctioninginstrument module 91, for example, can include stored instructions suchthat after failing to detect any signal from its adjacent instrumentmodule 91, such module begins listening to the next nearest mostinstrument module 91.

As with other non-hardwired telemetry options, when implementingacoustics, battery life management is key to ensuring a sufficientlylong operating time. In order to be robust, sufficient battery life,e.g., for at least six months, can be readily allocated on each riserasset in order for it to meet the demands of its various subsystemsthroughout the drilling/completion campaign. The use of seawaterbatteries, as an alternative power source, can help compensate for suchlimitation. Additionally, the instrument modules 91 can be programmed toprovide periodic transmission of data, for example, once every 30seconds or longer, so that the transceivers 109 are in the listen modefor a majority of the time. Further, the instrument modules 91 can beprovided sufficient memory 105, not only to store data for the periodictransmissions, but to store data for a preselected period of time in theevent data communication is disrupted while remedial action is beingcarried out. According to another embodiment, the acoustics systemprovides multiband transmission to both compensate for single bandsignal disruption, when occurring, and to increase transmissionbandwidth.

Electromagnetic or EM (radio) communications can be implemented,although they are not widely used for underwater applications. Afundamental problem with EM is the difficulties encountered withproviding data communication through the conductive seawater, which hastraditionally required relatively long antennas and high power. EMcommunication offers a significant advantage with respect toinstallation, but at the expense of providing a relatively limitedrange. For example, a range of 180 feet limits the communication baudrate to double digits, and broadband communication is typically limitedin transmission range to a few inches at best. One of the mostsignificant advantages of using EM, however, is its ability to provide apractical alternative to hardwire. In such case, each measurementinstrument module 91 can contain a sealed EM transceiver adjacent eachriser joint connector, preferably located so that they are in closeproximity of each other transceiver when the riser joints 29 areconnected, thus enabling broadband communication. Data between riserconnectors of each single riser joint 29 is then communicated viahardwire. The sensor 103 and remaining hardware can advantageously belocated somewhere (as desired) along the length of the riser joint 29,directly connected to the aforementioned hardwire line. Additionally,such EM communications technology can be augmented with laser oracoustic communications, to provide an overall more robust datatelemetry scheme.

Laser telemetry (optical wave) technology can further be utilized.Although laser telemetry requires more pointing precision thanacoustics, laser telemetry is readily achievable, especially whenimplemented on the relatively straight riser joints 29. Optical waves,however, are affected by scattering.

Regardless of which communication medium or media 95 are utilized, apreselected level of fault tolerance must be achieved. It should beassumed that components of the measurement instrument modules 91 on eachriser asset may malfunction from time to time. This malfunctioning,however, may not be a direct cause of the electronics, but may beassociated with the harsh environment/handling that the equipment issubjected to during operation or deployment. Various embodiments of thesubsurface communication medium or media 95, nevertheless, must operatewhen the electronics on one or more riser assets are not in operation.The fault tolerant options selected are a function of the environment,the type of riser system, and the desired operational performance. A fewexample of fault tolerance data telemetry options are: use of riserasset re-sequencing, use of variable power, use of hardwired jumpers,use of ROV replaceable data telemetry stations, and use of enhancedonboard RAM.

As noted previously, the riser asset re-sequencing option prescribes afault tolerance methodology whereby data is transmitted to cover a spanof more than one riser asset, and whereby each measurement instrumentmodule 91 acts on the data intended for it, and ignores the rest. In thecase of a fault in a riser joint 29 or other riser asset of the riserstring 23 carrying a measurement instrument module 91, a signal from thesurface can be provided to re-sequence the transceivers 109 to bypassthe malfunctioning module 91. This is possible because the range of thesignal of the instrument modules 91 can be given to cover two or moreriser assets.

The variable power option prescribes a fault tolerance methodologywhereby, in the context of acoustics, for example, the instrument module91 would tune the transceiver 109 so that it would normally onlycommunicate with the station directly above or below it. In the case ofa fault, a surface signal would be provided which would instruct eachmeasurement instrument module 91 to broadcast at higher power, reportingat least the two nearest stations. Such a scheme, among others, can beused to determine the location of the fault, and instruct thefunctioning instrument modules 91 just above and below the faultyinstrument module 91 to operate at higher power, returning the remainingmodules 91 to the normal power consumption mode.

The hardwire jumper fault tolerance methodology prescribes a remedialoption that would require ROV intervention. In this scenario, amalfunctioning measurement instrument module 91 can be accessed byhardwire jumpers between it and the stations directly above and below.

The ROV replaceable data telemetry station option prescribes a faulttolerance methodology similar to that of the hardwire option, except theentire hardware package, usually less the sensor 103 and associateddelivery/installation equipment, is easily replaced using an ROV.

The on-board RAM option prescribes a fault methodology whereby someamount of excess on-board RAM or other memory 105 would be provided inorder to store data in the event the data telemetry portion of theinstrument module 91 is not functioning, while the sensor 103 continuesto gather data. The amount of memory 105 is a linear function of theamount of time expected for remedial action. A very robust system wouldinclude one that can locally store several months of sensor data, aswell as several days of sensor data from the riser asset directly below.This clearly depends on the amount and volume of information theoperator wishes to have gathered by the sensors 103 and the packagingcost of the onboard memory 105.

While a few options for fault tolerance were described above, it shouldbe noted that various other fault tolerance options can be incorporatedin all subsystems. This can include ship-to-shore data integrity checksas well as database availability at a redundant data center.

Regardless of the subsurface communication medium or media, according toan embodiment of the present invention, the shipboard computer 41receives the various sensor data, sorts it, adds additional information(i.e., field name, well number, and other relevant information), andforwards it to the shore-based data warehouse 63 via a communicationnetwork such as, for example, global communication network 61. As abackup, the shipboard computer 41 maintains the entire history for theparticular well over which the drilling/completion/production operation,etc. is taking place.

According to the illustrated embodiment of the system, the shipboardcomputer 41 on regular intervals, receives the latest riser asset loadhistory for each of its riser assets in the frequency domain from thedata warehouse 63. The shipboard computer 41 also performs routinemonitoring of the condition of the various assets, for example, severaltimes a minute.

The shipboard computer 41 can advantageously provide a primary alarmsystem for when either an anomaly is detected directly from aninstrument module 91, or when the accelerated fatigue damage ispredicted. Examples of an anomaly in the sensed data would be excessivestresses, deflections, accelerations, etc. Built-in routines provided bycomputer program elements, described in detail below, can determine thesource of the anomaly, and alarm the operator as to the possible rootcause. For example, vortex induced vibration (“VIV”) caused by sheddingof vortices VX may be reported on a 300′ section of the riser some 500′below the water line if it is experiencing high frequency alternatingstresses in a cross flow motion. In such an event, the shipboardcomputer 41 may perform additional monitoring of the excited riser joint29 or section, and predict the condition of the riser joint 29 orsection several days, weeks, or months in advance. It is noted that,according to an embodiment of the present invention, the onshore riserlifecycle management server 51 includes computer program elements toperform a more comprehensive health monitoring checks, but at theexpense of a time lag in reporting the results. Further, having detectedsuch an event, the shipboard computer 41, through the shipboardcommunication network 43 can provide commands to a tensioner controller39 (FIG. 5) to provide control of the tensioning system 35, 35′, toreduce or mitigate the effect of the VIV.

As perhaps best shown in FIGS. 6 and 7, various embodiments of thepresent invention include riser lifecycle management program 120 storedin the memory 57 of the riser lifecycle management server 55 to monitorand manage a plurality of riser assets including riser joint 29positioned at a plurality of separate vessel locations (e.g., on ordeployed by each vessel 27). Similarly, various embodiments of thepresent invention include riser asset management program 120′ stored inthe memory 47 of the shipboard computer 41 to monitor and manage aplurality of riser assets including riser joint 29 assigned to thespecific vessel 27. As most of the computer program elements executed bythe shipboard computers 41 and the riser lifecycle management server 51are very similar in function, the computer program elements willprimarily be described with respect to those either solely or jointlyexecuted by the riser lifecycle management server 51.

Note, the riser lifecycle management program 120 and the riser assetmanagement program 120′, can be in the form of microcode, programs,routines, and symbolic languages that provide a specific set or sets ofordered operations that control the functioning of the hardware anddirect its operation, as known and understood by those skilled in theart. Note also, neither the riser lifecycle management program 120 northe riser asset management program 120′, according to an embodiment ofthe present invention, need to reside in its entirety in volatilememory, but can be selectively loaded, as necessary, according tovarious methodologies as known and understood by those skilled in theart. Further, the riser lifecycle management program 120 and riser assetmanagement program 120′ each include various functional elements as willbe described in detail below, which have been grouped and named forclarity only. One skilled in the art would understand that the variousfunctional elements need not be physically implemented in any hierarchy,but can be readily implemented as separate objects or macros. Variousother conventions can be utilized as well, as would be known andunderstood by one skilled in the art. Further note, although thefollowing functional element description is directed primarily to riserjoint 29, one skilled in the art would recognize that such functionalitycan encompass other riser assets of interest.

According to an embodiment of the present invention, the riser lifecyclemanagement program 120 can include a riser asset deployment and locationtracker 121, a riser asset load history manager 123, a riser maintenancemanager 125, and a riser asset load data acquisition manager 127, thatwhen executed by the riser lifecycle management server 51 cause theserver 51 to perform various operations, described below. The riserasset deployment and location tracker 121 can function to receivesubsurface deployment and relative location positioning data for aplurality of riser joints 23 adapted to be deployed to form variousmarine riser strings 23 associated with the plurality of vessels 27.

The riser load history manager 123 manages and manipulates the loadhistory. According to an embodiment of the present invention, the riserload history manager 123 includes a riser asset load history receiver131, a riser asset load history recorder 133, a riser asset load historytime to frequency domain data transformer 135, and a riser asset loadhistory transmitter 137. The riser asset load history receiver 131 canfunction to receive load history data for each of the riser joints 29 orother riser assets from each vessel 27 and to store the load history ina database such as, for example, database 65. The riser asset loadhistory recorder 133 can function to form and store a time-domain basedload history table which, as described previously, can provide real-timeriser loading imposed on each of the riser joints 29 or other assets foreach vessel 27 or other facilities for a preselected length of time, andcan function to store maximum amplitudes for one or more parameters ofinterest for each of the riser joints 29 or other riser assets, forexample, in the form of a maximum amplitudes matrix, as describedpreviously. The riser asset load history time to frequency domain datatransformer 135 can function to transform time-domain based load historydata into a frequency domain and to provide a frequency-domain basedload history table, as described previously, to thereby provide storagefor substantially all available riser joint load history for each of theriser joints 29 or other riser assets, in order to reduce storagerequirements and to reduce an amount of computing time necessary toanalyze the data. The riser asset load history transmitter 137 canfunction to send the frequency-domain based riser joint load history fora subset of the riser joints 29 or other riser assets forming anassociated deployed riser string 23, to a shipboard computer 41 carriedby the vessel 27 deploying the subset of the plurality of riser joints29 or other riser assets. This can be accomplished over a communicationnetwork, such as, for example, global communication network 61.

The riser maintenance manager 125 manages determining and schedulingmaintenance requirements. The riser maintenance manager 125 can includea riser asset fatigue determiner 141, a riser asset fatigue lifeestimator 143, a subsea wellhead system analyzer 145, riser assetmaintenance scheduler 147, and a riser asset maintenance event notifier149. The riser asset fatigue determiner 141 can function to estimate acondition of each of the riser joints 29 and other riser assets ofinterest from the riser joint load data received from the shipboardcomputers 41 or riser stress data (as a function of time) eitherreceived from the shipboard computers 41 or determined from the receivedriser joint load data by the server 51, or a combination thereof, foreach riser joint 29 or other riser asset of interest across the spectrumof vessels and facilities in communication with the riser lifecyclemanagement server 51. The riser asset fatigue life estimator 143 canfunction to estimate remaining fatigue life for each of the riser joints29 or other riser asset of interest from the received load data, storedload history data, and specific riser asset material properties data foreach respective riser asset, or a combination thereof, and to issue analert when the fatigue life of a respective riser asset drops below apreset fatigue life trigger level requiring inspection. The subseawellhead system analyzer 145 can function to predict a magnitude of loadimposed on a subsea wellhead system 25 based upon riser load historydata for a subset of the riser joints 29 and/or forming an associatedmarine riser string 23. The riser asset maintenance scheduler 147 canfunction to generate a schedule of routine maintenance events for eachriser joints 29 or other riser asset of interest, based upon thereceived load data, the stored load history, and respective riser assetmaterial properties, or a combination thereof, and to generateunscheduled maintenance events responsive to a load data anomaly whenoccurring detected in the received load data and resulting in engagementof a preset fatigue life trigger level requiring inspection. The riserasset maintenance event notifier 149 can function to issue an onlinealert providing a reminder to a user of a forthcoming scheduledmaintenance event, and can function to issue an online alert indicatingan unscheduled maintenance event requirement when existing.

The riser asset load data acquisition manager 127 manages and reviewsthe qualities of the acquired riser asset load data. According to anembodiment of the present invention, the riser asset load dataacquisition manager 127 includes a riser asset sensor fault manager 151,a riser asset sensor anomaly detector 153, a riser asset sensor datapredictor 155, a riser asset sensor integrity checker 157, and a riserasset sensor data removal manager 159. The riser asset sensor faultmanager 151 can function to identify a malfunctioning riser jointmeasurement instrument module 91 associated with one or more of theplurality of deployed riser joints forming the marine riser string 23,and to signal one or more adjacent riser joint measurement instrumentmodules 91 to bypass the malfunctioning riser joint measurementinstrument module 91 or to otherwise implement one or more of thepreviously fault tolerance methodologies described previously, tothereby provide substantially continuous load data acquisition for eachriser joint measurement instrument module 91 positioned below themalfunctioning riser joint measurement instrument module 91. Note, aswill be understand by one skilled in the art, the type of faultmethodology implemented is dependent upon the type of communicationmedia utilized, the type of sensors associated with the instrumentmodules 91, and the spacing of the modules 91 which may or may not bepositioned on each riser joint 29 forming the riser string 23.

The riser asset sensor anomaly detector 153 can function to detect aload data anomaly when occurring responsive to the received load/loadhistory data. The riser asset sensor data predictor 155 can function togenerate predicted sensor data that a riser joint measurement instrumentmodule 91 associated with one or more deployed riser joints 29 or otherriser assets of interest, should report based on recent load history forthe respective instrument module 91 and/or those provided by otheradjacent instrument modules 91 deployed on the same riser string 23. Theriser asset sensor integrity checker 157 can function to compare sensorreadings of a riser joint measurement instrument module 91 associatedwith one or more deployed riser joints 29 or other riser assets forminga same deployed riser string 23 to sensor readings for at least twoadjacent riser joints 29 or other riser assets forming the riser string23 to thereby determine an integrity of the riser joint measurementinstrument module 91, and to flag sensor readings emanating from therespective instrument module 91 when the integrity is determined to bequestionable. The riser asset sensor data removal manager 159 canfunction to remove flagged data associated with a faulty sensor fromactive record data, and to optionally replace the removed data withcorresponding predicted data generated by the riser sensor datapredictor 155.

Beneficially the functionality provided by the riser lifecyclemanagement programs 120, 120′ provides asset managers real-time andstored database information to maintain the various riser assets ofinterest. As an example, according to an embodiment of the presentinvention, when a user logs into the system, the user would see thevarious vessels 27 equipped according to embodiment of the presentinvention and associated with the user, along with graphical userinterface fields which allow the user to query such data by vessel,riser asset, or field. The vessel query can beneficially provide theuser a list all the riser assets allocated to the vessel and provide afurther breakdown of those riser assets that are currently deployed, areon deck, or are out for maintenance, along with the expected returndate. This view of the data can also be used to generate a list ofupcoming scheduled maintenance events. The riser asset query canbeneficially provide the user with an estimate of the operational lifeused by a particular riser asset, along with the details of the mostdamaging events (i.e., a certain hurricane event). This query can alsoprovide detailed information on riser maintenance history andcritical/relevant manufacturing information. Individual riser assets canpotentially be moved from one vessel 27 to another with their historyintact. The field query can provide the user with information toreconstruct a riser string configuration of any particular deployment.The availability of the time stamp for each riser deployment permitsdetermination of where, in the water column, each riser asset waslocated for any particular drilling campaign. This information can alsobe used to automatically create input for a riser analysis program.

As noted above, the vessel riser asset management program 120′ cangenerally include much of the functionality provided by the riserlifecycle management program 120, but preferably at a local vessellevel, rather than at an operational program, fleet, or enterpriselevel. Accordingly, the vessel riser management program 120′ can includea riser asset deployment and location tracker 121′, a riser asset loadhistory manager 123′, a riser maintenance manager 125′, and a riserasset load data acquisition manager 127′, that when executed by therespective shipboard computer 41, cause the computer 41 to performvarious operations, described below.

The riser asset deployment and location tracker 121′ can function toreceive subsurface deployment and relative location positioning data fora plurality of riser joints 23 adapted to be deployed to form a marineriser string 23 associated with the respective vessel 27.

The riser load history manager 123′ manages and manipulates the loadhistory for the riser joint 29 or other assets of interest associatedwith the respective vessel 27. Although much of the functionality ispreferably implemented by the riser lifecycle management server 51,according to an embodiment of the present invention, the riser loadhistory manager 123′ nevertheless is provided and correspondinglyincludes a riser asset load history receiver 131′, a riser asset loadhistory recorder 133′, a riser asset load history time to frequencydomain data transformer 135′, and a riser asset load history transmitter137′, to at least partially perform functions performed by the riserlifecycle management server 51.

According to an embodiment of the present invention, the riser assetload history receiver 131′ can function to receive load history data foreach of the of riser joints 29 or other riser assets from the riserlifecycle management server 51 and to store the load history in adatabase such as, for example, database 49. Such data is typicallyfrequency-domain based data. According to an embodiment of the presentinvention, a riser asset load history time to frequency domain datatransformer 135′ can function to also, or alternatively, independentlytransform time-domain based load history data into a frequency domainand to provide a frequency-domain based load history table, as describedpreviously, to thereby provide storage for substantially all availableriser joint load history for each of the riser joints 29 or other riserasset of interest associated with the deployed riser string 23 for therespective vessel 27, in order to reduce storage requirements and toreduce an amount of computing time necessary to analyze the data. Theriser asset load history recorder 133′ can function to form and store atime-domain based load history table which, as described previously, canprovide real-time riser loading imposed on each of the riser joints 29or other assets for each vessel 27 or other facilities for a preselectedlength of time, and can function to store maximum amplitudes for one ormore parameters of interest for each of the riser joints 29 or otherriser assets, for example, in the form of a maximum amplitudes matrix,as described previously. The riser asset load history transmitter 137′can function to send either raw data, time-domain based data, or thefrequency-domain based riser joint load history for the riser joints 29or other riser assets of interest forming an associated deployed riserstring 23, to the riser lifecycle management server 51 over acommunication network, such as, for example, global communicationnetwork 61.

The riser maintenance manager 125′, similar to that for the riserlifecycle management program 120, can manage determining and schedulingmaintenance requirements for riser joints 29 or other riser assets ofinterest, particularly those associated with the specific vessel 27. Theriser maintenance manager 125′ can include a riser asset fatiguedeterminer 141′, a riser asset fatigue life estimator 143′, a subseawellhead system analyzer 145′, riser asset maintenance scheduler 147′,and a riser asset maintenance event notifier 149′. The riser assetfatigue determiner 141′ can function to estimate a condition of each ofthe riser joints 29 and other riser assets of interest from the riserjoint load data, e.g., riser stress data (as a function of time) eitherreceived from the measurement instrument modules 91 or determined fromthe data received from the measurement instrument modules 91, storedriser asset load history data, and riser asset material properties, or acombination thereof, for each riser joint 29 or other riser asset ofinterest generally for the specific vessel 27 or facility.

The riser asset fatigue life estimator 143′ is similarly adapted toestimate remaining fatigue life for each of the riser joints 29 or otherriser asset of interest from the received load data, stored load historydata, and specific riser asset material properties data for eachrespective riser asset, or a combination thereof, and to issue an alertwhen the fatigue life of a respective riser asset drops below a presetfatigue life trigger level requiring inspection. The subsea wellheadsystem analyzer 145′ is further similarly adapted to predict a magnitudeof load imposed on a subsea wellhead system 25 based upon the receivedload data and/or stored load history data associated with the deployedriser joints 29 or other riser assets of interest forming the respectivemarine riser string 23.

The riser asset maintenance scheduler 147′ can function to generate aschedule of routine maintenance events for each riser joints 29 or otherriser asset of interest, based upon the received load data, the storedload history, and respective riser asset material properties, or acombination thereof, and to generate unscheduled maintenance eventsresponsive to a load data anomaly when occurring detected in thereceived load data and resulting in engagement of a preset fatigue lifetrigger level requiring inspection. The riser asset maintenance eventnotifier 149′ can function to issue an online alert providing a reminderto a user of a forthcoming scheduled maintenance event, and can functionto issue an online alert indicating an unscheduled maintenance eventrequirement when existing.

The riser asset load data acquisition manager 127′ manages and reviewsthe qualities of the acquired riser asset load data. According to anembodiment of the present invention, the riser asset load dataacquisition manager 127′ includes a riser asset sensor fault manager151′, a riser asset sensor anomaly detector 153′, a riser asset sensordata predictor 155′, a riser asset sensor integrity checker 157′, ariser asset sensor data removal manager 159′, and a riser asset loadsensor data receiver 161.

The riser asset load sensor data receiver 161 can function to receiveload data collected from the measurement instrument modules 91 when theriser joints 29 or other riser assets of interest are deployed in placeto form the riser string 23 and/or during deployment. The riser assetsensor fault manager 151′ can function to identify a malfunctioningriser joint measurement instrument module 91 associated with one or moreof the plurality of deployed riser joints forming the marine riserstring 23, and to signal one or more adjacent riser joint measurementinstrument modules 91 to bypass the malfunctioning riser jointmeasurement instrument module 91 or to otherwise implement one or moreof the previously fault tolerance methodologies described previously, tothereby provide substantially continuous load data acquisition for eachriser joint measurement instrument module 91 positioned below themalfunctioning riser joint measurement instrument module 91.

The riser asset sensor anomaly detector 153′ can function to detect aload data anomaly when occurring responsive to the received load data.The riser asset sensor data predictor 155′ can function to generatepredicted sensor data that each riser joint measurement instrumentmodule 91 associated with one or more deployed riser joints 29 or otherriser assets of interest, should report based on recent load history forthe respective instrument module 91 and/or those provided by otherinstrument modules 91 deployed on the same riser string 23. The riserasset sensor integrity checker 157′ can function to compare sensorreadings of a riser joint measurement instrument module 91 associatedwith one or more deployed riser joints 29 or other riser assets forminga same deployed riser string 23 to sensor readings for at least twoadjacent riser joints 29 or other riser assets forming the riser string23 to thereby determine an integrity of the riser joint measurementinstrument module 91, and to flag sensor readings emanating from therespective instrument module 91 when the integrity is determined to bequestionable. The riser asset sensor data removal manager 159′ canfunction to remove flagged data associated with a faulty sensor fromactive record data, and to optionally replace the removed data withcorresponding predicted data generated by the riser sensor datapredictor 155′.

The riser lifecycle management program 120 and/or riser asset managementprogram 120′ beneficially can interface with a riser tension managementprogram 170 which can record and manage riser tension, or alternatively,can include various program elements to perform such function.Accordingly, an embodiment of the present convention can provide a risertensioner recorder 171, a riser tensioner manager, and a vortex inducedvibration alert manager. The riser tensioner recorder 171 can functionto record tension settings, applied riser tension, and tensioner strokefor a riser tensioner system connected to a marine riser string 23. Theriser tensioner manager 173 can function to provide data usable by acontroller 39 of a riser tensioner system 35, 35′, to adjust a tensionersetting to continually apply optimum riser tension responsive to riserstress data determined from the received load data. The vortex inducedvibration alert manager 175 can function to detect an impending orongoing vortex induced vibration condition and approximate locationthereof along a length of the marine riser string 23 when existingresponsive to at least the received load data, to signal an emergencyalert thereof responsive to detecting the vortex induced vibrationcondition, and to determine an action to reduce or mitigate the detectedvortex induced vibration. If implemented in the riser lifecyclemanagement program 120, such program element provides a backup for thevessel 27, albeit, potentially with a significant lag.

Various embodiments of the present invention also include variousmethods relating to monitoring and managing a plurality of marine riserassets. According to an embodiment of the present invention, a method ofmonitoring and managing a plurality of marine riser assets can includethe steps of receiving riser joint identification data from a riserjoint identification sensor 73 positioned within a well bay 31 for eachof a plurality of riser joints 29 (or other riser assets of interest)during deployment from the respective vessel 27 to form a marine riserstring 23, and determining a relative deployed position location of theeach of the riser joints 29 deployed from the vessel 27 to form themarine riser string 23. Each of the riser joints 29 correspondinglyinclude indicia (e.g., RFID tag 71) readable by a riser jointidentification sensor 73 to separately identify each one of the riserjoints 29 from each other of the riser joints 29. The method can alsoinclude receiving load data for each of the riser joints 29 from aplurality of riser joint measurement instrument modules 91, andmonitoring loading of each of the deployed riser joints 29 responsive tothe load data provided by the riser joint measurement instrument modules91.

The method can also include estimating a riser joint loading conditionfor each of the deployed riser joints 29 in response to the load data ofone or more of the deployed riser joints 29, and providing an alarm inresponse to the estimated loading condition nearing an operating designor service envelope one or more of the deployed riser joints 29. Themethod can also, or alternatively, include estimating fatigue damage tothe deployed riser joints 29 in response to the load data of the one ormore of the deployed riser joints, and providing an alarm in response tothe estimated fatigue damage exceeding a preselected operational limit.The method can also, or alternatively, include detecting an anomaly inthe load data of one or more of the deployed riser joints 29, whenexisting, and providing an alarm in response to the detection of theanomaly.

The method can also, or alternatively, include receiving load data foreach of the riser joints 29 from a plurality of riser joint measurementinstrument modules 91, monitoring loading of each of the deployed riserjoints in response to the load data provided by the riser jointmeasurement instrument modules 91, monitoring tension settings, appliedriser tension, and tensioner stroke of a tensioning system 35, 35′, andproviding data to a tensioner controller 39 to control adjusting thetensioning system tension settings to continually apply optimum risertension in response to the load data.

According to another embodiment, a method of monitoring and managing aplurality of marine riser assets includes the steps of determining arelative deployed position location of the each of a plurality of riserjoints 29 (or other riser assets of interest) deployed from a vessel 27to form a marine riser string 23, receiving load data for each of thedeployed riser joints 29 from a plurality of riser joint measurementinstrument modules 91 connected to at least a subset of the deployedriser joints 29, monitoring loading of each of the deployed riser joints29 in response to the load data provided by the riser joint measurementinstrument modules 91, estimating a riser joint loading condition foreach of the deployed riser joints 29 in response to the load data of oneor more of the plurality of deployed riser joints 29, and providing analarm in response to the estimated loading condition nearing anoperating design or service envelope for one or more of the deployedriser joints 29.

The method can also include a shipboard computer 41 sending riser jointdeployment location data and relative deployed position location andloading data for the deployed riser joints 29 to a central databasewarehouse (e.g., data warehouse 63) located remote from the vessel 27and adapted to receive such data from a plurality of such vessels 27each deploying riser joints 29 forming one or more riser strings 23. Themethod can also or alternatively include detecting an impending orongoing vortex induced vibration condition and approximate locationthereof along a length of the riser string 23, and adjusting tensioningof the riser string 23 to reduce or mitigate the detected vortex inducedvibration condition.

According to another embodiment, a method of monitoring and managing aplurality of marine riser assets, e.g., positioned at one or moreseparate vessel locations, can include the steps of receiving riserjoint deployment and location data for each one of a plurality ofdeployed riser joints 29 (or other riser assets of interest) deployed atone of a plurality of separate vessel locations carrying the respectiveriser joint 29, receiving from an associated shipboard computer 41,riser joint load history data for each of the riser joints 29 deployedat the plurality of separate vessel locations, transforming riser jointload history data received in the time domain into load history data inthe frequency domain, and determining a level of damage of each of thedeployed riser joints 29 in response to the received riser joint loadhistory data and/or the transformed riser joint load history data.

The method can also, or alternatively, include estimating remainingriser joint serviceable life in response to riser joint materialproperties for each respective riser joint 29 and the received riserjoint load history data and/or the transformed riser joint load historydata, scheduling routine maintenance events for each of the deployedriser joints 29, and scheduling an unscheduled (e.g., immediate actionor emergency) maintenance event in response to a load history anomaly(e.g., unexpected incident) in the received riser joint load historydata resulting in engagement of a preset operational life trigger levelrequiring inspection. The method can also, or alternatively, furtherinclude reconstructing a riser string configuration of any one of theriser joints 29 deployed at any one of the plurality of separate vessellocations from the riser joint deployment and location data associatedwith the respective riser string 23, and predicting a magnitude of aload imposed on a subsea wellhead system 25 associated with therespective riser string 23 from corresponding riser load history datafor at least a subset of a plurality of riser joints 29 forming therespective riser string 23. Note, each riser joint 29 need not have arespective instrument module 91 attached thereto. Still further, themethod can also, or alternatively, include sending riser load historydata in the frequency domain for each one of the plurality of deployedriser joints 29 to the respective shipboard computer 41 located at theassociated one of the plurality of vessel locations carrying therespective deployed riser joint 29.

It is important to note that while embodiments of the present inventionhave been described in the context of a fully functional system, thoseskilled in the art will appreciate that the mechanism of at leastportions of the present invention and/or aspects thereof are capable ofbeing distributed in the form of a computer readable medium in a varietyof forms storing instructions for execution on a processor, processors,or the like, and that the present invention applies equally regardlessof the particular type of signal bearing media used to actually carryout the distribution. Examples of the computer readable media includebut are not limited to: nonvolatile, hard-coded type media such as readonly memories (ROMs), CD-ROMs, and DVD-ROMs, or erasable, electricallyprogrammable read only memories (EEPROMs), recordable type media such asfloppy disks, hard disk drives, CD-R/RWs, DVD-RAMs, DVD-R/RWs,DVD+R/RWs, flash drives, and other newer types of memories, andtransmission type media such as digital and analog communication linkscapable of storing instructions. Such media can include both operatinginstructions and operations instructions related to the riser lifecyclemanagement program 120, the riser asset management program 120′, theriser tension or management program 170, and the computer executablemethod steps, described above.

Embodiments of the present invention provide several advantages. Forexample, various embodiments of the present invention provide a systemincluding a central database that can be used by field and maintenancepersonnel to maintain and communicate critical riser information. Suchcentral database also advantageously can provide early visibility ofupcoming maintenance event and plan them accordingly. The warehousing ofmarine riser data can advantageously result in a number of otheropportunities for the management and maintenance of marine fielddevelopment assets. For example, the riser load history information canbe used to improve riser joint design, which is linked to having betterknowledge of actual riser load history. Additionally, the riser loadhistory information for a given drilling or production operation,through extrapolation or by a separate riser analysis program, can beused to predict the magnitude of the loads imposed on the subseawellhead system. This information, in turn, can then be used to optimizethe configuration of upcoming subsea wells in the same general area(i.e., same field development). Various embodiments of the presentinvention also advantageously allow for substantial fault tolerance inthe subsystem that is deemed to be most vulnerable, namely the datatelemetry equipment, along with additional fault tolerance features.

Various embodiments of the present invention also provide sufficientflexibility to communicate across third-party assets. For example, thedatabase can retain the riser tensioner key parameters such as strokeand applied riser tension. Such systems integration, along withreal-time load data, can allow direct manipulation of the risertensioning system to improve performance and extend the life of riserjoints.

Various embodiments of the system can automatically notify the user ofboth routine and unscheduled maintenance events. A routine maintenanceevent is one that is scheduled sometime in advance, but may have beenaided by load history information in the database. An unscheduledmaintenance event is one associated with an unexpected incident. Forexample, one or more riser joints in a string that has been subjected toa direct hit by a hurricane may reach a preset fatigue life triggerlevel, requiring an inspection of the riser joint at the very least. Insuch a scenario, the operator would have a high degree of confidencethat the remaining riser assets are suitable for marine deployment,reducing the down time associated with inspection of the entire riserstring. Various embodiments of the system can also automatically notifythe user of both routine and unscheduled maintenance events.

This application is a continuation of U.S. patent application Ser. No.13/300,155, titled “Riser Lifecycle Management System, Program Product,and Related Methods,” filed on Nov. 18, 2011, which is a continuation ofU.S. patent application Ser. No. 12/029,376, titled “Riser LifecycleManagement System, Program Product, and Related Methods,” filed on Feb.11, 2008, now U.S. Pat. No. 8,074,720, and is related to U.S. patentapplication Ser. No. 10/951,563, now U.S. Pat. No. 7,328,741, titled“System for Sensing Riser Motion,” filed on Sep. 28, 2004, eachincorporated herein by reference in its entirety.

In the drawings and specification, there have been disclosed a typicalpreferred embodiment of the invention, and although specific terms areemployed, the terms are used in a descriptive sense only and not forpurposes of limitation. The invention has been described in considerabledetail with specific reference to these illustrated embodiments. It willbe apparent, however, that various modifications and changes can be madewithin the spirit and scope of the invention as described in theforegoing specification. For example, although the description primarilyfocuses on application to drilling platforms and drilling risers,various embodiments of the present invention equally apply to TLP andSPAR production platforms/risers.

That claimed is:
 1. A non-transitory computer readable medium embodyingprogram code for monitoring and managing a plurality of marine riserassets, the program code comprising a set of instructions, stored on thecomputer readable medium, that when executed by a computer, cause thecomputer to perform the operations of: receiving riser jointidentification data retrieved from each of a plurality of riser jointsduring a subsea deployment thereof from a vessel to form a marine riserstring, each separate one of the plurality of riser joints carrying ariser joint identification indicator connected thereto, each riser jointidentification indicator carrying or containing information about therespective riser joint sufficient to provide for separately identifyingthe respective riser joint from each other of the plurality of riserjoints deployed during the subsea deployment; and identifying eachseparate one of the respective plurality of riser joints deployed fromthe vessel responsive to the riser joint identification data retrievedfrom the corresponding riser joint identification indicator during thesubsea deployment of the respective riser joint to thereby track thesubsea deployment thereof.
 2. A non-transitory computer readable mediumas defined in claim 1, wherein the operations further comprise: trackingthe subsea deployment of each of the plurality of riser joints.
 3. Anon-transitory computer readable medium as defined in claim 2, whereineach riser joint identification indicator comprises a radio frequencyidentification indicator.
 4. A non-transitory computer readable mediumas defined in claim 2, wherein the operations further comprise:recording a timestamp indicating when each respective riser joint of theplurality of riser joints was deployed.
 5. A non-transitory computerreadable medium as defined in claim 1, wherein the operations furthercomprise: determining a relative deployed position location of the eachof the plurality of riser joints deployed from the vessel.
 6. Anon-transitory computer readable medium as defined in claim 5, whereinthe relative deployed position location comprises a position location ofthe respective deployed riser joint along a length of the deployedmarine riser string relative to other of the plurality of deployed riserjoints, the waterline, or other relative position reference.
 7. Anon-transitory computer readable medium as defined in claim 1, whereinthe operations further comprise: receiving riser joint identificationdata retrieved from the riser identification indicator of eachrespective one of one or more of the plurality of riser joints duringoperational retrieval thereof using a riser joint identification sensor,the information carried or contained by the respective one or more riseridentification indicators being sufficient to provide for separatelyidentifying the corresponding retrieved riser joint from each other ofthe plurality of riser joints; and identifying the respective one ormore operationally retrieved riser joints responsive to the riser jointidentification data retrieved from the corresponding riser jointidentification indicator during the operational retrieval of therespective riser joint to thereby track the retrieval thereof.
 8. Anon-transitory computer readable medium as defined in claim 7, whereinthe operations further comprise tracking the subsea deployment andretrieval of each of the plurality of riser joints.
 9. A non-transitorycomputer readable medium as defined in claim 8, wherein the operationsfurther comprise: recording a timestamp indicating when each respectiveriser joint of the plurality of riser joints is deployed; and recordinga timestamp indicating when each respective riser joint of the pluralityof riser joints is retrieved.
 10. A non-transitory computer readablemedium as defined in claim 1, wherein the operations further comprise:predicting a magnitude of a load imposed on a subsea wellhead systemassociated with the riser string responsive to corresponding riser loaddata for at least a subset of a plurality of riser joints forming themarine riser string.
 11. A non-transitory computer readable medium asdefined in claim 1, wherein the riser joint identification data isretrieved from the riser identification indicator of each respective oneof the plurality of riser joints using a riser joint identificationsensor positioned within a well bay on the vessel, and wherein theoperations further comprise: receiving the riser joint identificationdata retrieved using the riser joint identification sensor duringdeployment of the plurality of riser joints; and virtually constructingthe marine riser string configuration responsive to the riser jointidentification data for each of the plurality of riser joints receivedduring deployment thereof.
 12. A non-transitory computer readable mediumas defined in claim 1, wherein the operations further comprise:receiving riser joint deployment location data and relative deployedposition location data for each of the plurality of deployed riserjoints from each of the plurality of vessels for storage in a centraldatabase warehouse located remote from the vessel and adapted to receivesuch data from the plurality of vessels; and virtually constructing ariser string configuration of any one of the respective plurality ofriser joints deployed at any one of the plurality of separate vessellocations responsive to the riser joint deployment and position locationdata associated with the respective marine riser string.
 13. Anon-transitory computer readable medium as defined in claim 12, whereinthe operations further comprise: receiving by the central databasewarehouse from each of the plurality of vessels, riser load history datafor each of the respective plurality of deployed riser joints; andpredicting a magnitude of a load imposed on a subsea wellhead systemassociated with the respective riser string responsive to correspondingriser load history data for at least a subset of the respectiveplurality of riser joints forming the respective riser string.
 14. Anon-transitory computer readable medium as defined in claim 1, whereineach of the plurality of riser joints carries a riser joint measurementinstrument module, and wherein the operations further comprise:receiving load data for each of the plurality of riser joints retrievedfrom a corresponding plurality of riser joint measurement instrumentmodules, the load data provided through relay of the data from each ofthe plurality of riser joints to a riser joint positioned adjacent therespective riser joint until reaching a riser load data receiver.
 15. Anon-transitory computer readable medium as defined in claim 1, whereinthe operations further comprise: receiving load data for each of theplurality of riser joints retrieved from a corresponding plurality ofriser joint measurement instrument modules connected thereto; monitoringloading of each of the plurality of riser joints when deployedresponsive to the load data provided by the plurality of riser jointmeasurement instrument modules; and estimating a deployed riser jointloading condition for each of the plurality of riser joints responsiveto the load data of one or more of the plurality of riser joints.
 16. Anon-transitory computer readable medium as defined in claim 15, whereinthe operation of estimating a deployed riser joint loading condition isperformed during operational deployment of the respective plurality ofriser joints, and wherein the operations further comprise: providing analarm responsive to the estimated deployed riser joint loading conditionnearing an operating design or service envelope of one or more of theplurality of deployed riser joints.
 17. A non-transitory computerreadable medium as defined in claim 1, wherein the operations furthercomprise: receiving load data for each of the plurality of riser jointsretrieved from a corresponding plurality of riser joint measurementinstrument modules connected thereto; and estimating fatigue damage toeach of the plurality of riser joints responsive to the load data of theone or more of the plurality of riser joints.
 18. A non-transitorycomputer readable medium as defined in claim 17, wherein the operationof estimating fatigue damage is performed during operational deploymentof the respective plurality of riser joints, and wherein the operationsfurther comprise: providing an alarm responsive to the estimated fatiguedamage of one or more of the plurality of deployed riser jointsexceeding a preselected operational limit.
 19. A non-transitory computerreadable medium as defined in claim 1, wherein the operations furthercomprise: receiving load data for each of the plurality of riser jointsretrieved from a corresponding plurality of riser joint measurementinstrument modules connected thereto; and detecting an anomaly in theload data of one or more of the plurality of riser joints when existing.20. A method as defined in claim 19, wherein the operation of detectingan anomaly in the load data is performed during operational deploymentof the respective plurality of riser joints, and wherein the operationsfurther comprise: providing an alarm responsive to the detection of theanomaly.
 21. A non-transitory computer readable medium as defined inclaim 1, wherein the operations further comprise: receiving load datafor each of the plurality of riser joints provided by a plurality ofriser joint measurement instrument modules, the load data providedthrough relay of the data from each of the plurality of riser joints toa riser joint positioned adjacent the respective riser joint untilreaching a riser load data receiver; monitoring loading of each of theplurality of deployed riser joints responsive to the load data providedby the plurality of riser joint measurement instrument modules; andmonitoring tensioning system tension settings, applied riser tension,and tensioner stroke.
 22. A non-transitory computer readable medium asdefined in claim 21, wherein the operations further comprise: providingdata to control adjusting the tensioning system tension settings toautomatically continually apply optimum riser tension responsive to theload data.
 23. A non-transitory computer readable medium as defined inclaim 1, wherein the operations further comprise: receiving load datafor each of the plurality of deployed riser joints provided by aplurality of riser joint measurement instrument modules connected to asubset of the plurality of riser joints when deployed operationally;monitoring loading of each of the plurality of deployed riser jointsresponsive to the load data provided by the plurality of riser jointmeasurement instrument modules; estimating a riser joint loadingcondition for each of the plurality of deployed riser joints responsiveto the load data of one or more of the plurality of deployed riserjoints; and providing an alarm responsive to the estimated loadingcondition nearing an operating design or service envelope for one ormore of the plurality of deployed riser joints.
 24. A non-transitorycomputer readable medium as defined in claim 1, wherein each of theplurality of riser joints carries a riser joint measurement instrumentmodule, and wherein the operations further comprise: comparing deployedriser joint sensor readings of a riser joint measurement instrumentmodule associated with one or more of the plurality of riser jointsforming the riser string, to sensor readings for at least two riserjoints of the plurality of riser joints forming the riser string tothereby determine an integrity of the riser joint measurement instrumentmodule and to flag sensor readings emanating from the respectiveinstrument module when the integrity is determined to be questionable.25. A non-transitory computer readable medium as defined in claim 24,wherein the operations further comprise: removing flagged dataassociated with a faulty instrument module from active record data; andoptionally replacing the removed data with corresponding predicted datagenerated by a riser sensor data predictor.
 26. A non-transitorycomputer readable medium as defined in claim 1, wherein each of theplurality of riser joints carries a riser joint measurement instrumentmodule, and wherein the operations further comprise: identifying amalfunctioning riser joint measurement instrument module associated withone or more of the plurality of riser joints forming the marine riserstring when operationally deployed; and signaling one or more adjacentriser joint measurement instrument modules to bypass the malfunctioningriser joint measurement instrument module to thereby providesubstantially continuous load data acquisition for each riser jointmeasurement instrument module positioned below the malfunctioning riserjoint measurement instrument module.
 27. A non-transitory computerreadable medium as defined in claim 26, wherein the computer is a localvessel computer located on board the vessel.
 28. A non-transitorycomputer readable medium embodying program code for monitoring andmanaging a plurality of marine riser assets, the program code comprisinga set of instructions, stored on the computer readable medium, that whenexecuted by a computer, cause the computer to perform the operations of:receiving riser joint identification data retrieved from each of aplurality of riser joints during a subsea deployment thereof from avessel to form a riser string, each separate one of the plurality ofriser joints carrying a riser joint identification indicator providingriser joint identification information, the identification informationretrieved from each respective riser joint identification indicatorusing a riser joint identification sensor; and determining a relativedeployed position location of the each of the plurality of deployedriser joints within the riser string responsive to the received riserjoint identification data.
 29. A non-transitory computer readable mediumas defined in claim 28, wherein the operations further comprisestracking the subsea deployment and retrieval of each of the plurality ofriser joints.
 30. A riser lifecycle management system for monitoring andmanaging a plurality of marine riser assets positionable at one or moreseparate floating vessels each having a floor, a well bay extendingtherethrough, and a local shipboard communication network carried by thevessel, the system comprising: a riser joint identification sensorpositioned at or adjacent the well bay; a communication network; aplurality of riser joints deployable from the vessel to form a riserstring, each riser joint carrying or containing an identificationindicator connected thereto, each riser joint identification indicatorcarrying or containing identification information about the respectiveriser joint, the identification information retrieved from eachrespective riser joint identification indicator using the riser jointidentification sensor and delivered through the communication network; acomputer in communication with the communication network and including aprocessor, and memory coupled to the processor; and riser assetmanagement program stored in the memory of the computer to monitor andmanage a plurality of riser assets, the riser asset management programincluding instructions that when executed by the computer, cause thecomputer to perform the operations of: receiving riser jointidentification data retrieved from each of the plurality of riser jointsduring a subsea deployment thereof from the vessel to form the riserstring, the riser joint identification data providing information aboutthe respective riser joint sufficient to provide for separatelyidentifying the respective riser joint from each other of the pluralityof riser joints when being deployed during the subsea deployment, andidentifying each separate one of the respective plurality of riserjoints deployed from the vessel responsive to the identificationinformation retrieved from the respective identification indicatorduring the subsea deployment of the respective riser joint connectedthereto to thereby track the subsea deployment thereof.
 31. A system asdefined in claim 30, wherein the operations further comprise: receivingriser joint identification data for one or more of the plurality ofriser joints during retrieval thereof, the riser joint identificationdata providing information about the respective riser joint sufficientto provide for separately identifying the respective riser joint beingretrieved from each other of the plurality of riser joints duringretrieval thereof; and identifying the respective one or more retrievedriser joints responsive to the riser joint identification data receivedby the riser joint identification sensor from the respectiveidentification indicator during the retrieval of the respective riserjoint to thereby track the retrieval thereof.
 32. A system as defined inclaim 31, wherein the operations further comprise tracking the subseadeployment and retrieval of each of the plurality of riser joints.
 33. Ariser lifecycle management system for monitoring and managing aplurality of marine riser assets positionable at one or more separatefloating vessels each having a floor, a well bay extending therethrough,and a local shipboard communication network carried by the vessel, thesystem comprising: a plurality of riser joints deployable from thevessel to form a riser string, each riser joint carrying anidentification indicator connected thereto; a riser joint identificationsensor positioned at or adjacent the well bay to retrieve riser jointidentification information from each of the plurality of riser joints; acomputer operably coupled to a communication network, the computerincluding a processor, and memory coupled to the processor; and riserasset management program stored in the memory of the computer to monitorand manage a plurality of riser assets, the riser asset managementprogram including instructions that when executed by the computer, causethe computer to perform the operations of: receiving riser jointidentification data retrieved from each of the plurality of riser jointsduring subsea deployment thereof from the vessel to form the riserstring, the riser joint identification data providing information aboutthe respective riser joint sufficient to provide for separatelyidentifying the respective riser joint from each other of the pluralityof riser joints being deployed, and determining a relative deployedposition location of the each of the plurality of deployed riser jointswithin the riser string responsive to the received riser jointidentification data.